Electric puse



Aug. 4, 1925. v 1,548,303

H. T. BUSSMANN ELECTRIC FUS E Fi1ed May 7. 1919 i To all whom it-fnay colncem.'

= a clear, full, and

amr-T. sussnaxm; or s'r. Louis, mussolini.

'Ennemis russ.

appunti@ nit my -1,'

Be it known than, Hmmfr. swings', a citizen of-the- United States, residing- 1n the city 'of St. Louis, in the State'of fissouri, have-invented a certain new and use ful Electric Fuse, of which the following is exact description, such as will enable otheis skilled in the art to make and'use tliesame.

My invention relates-to electric fuses and refers particular-l to'that typeof fuse knownv as therefil ablev cartridge ,fuse; yet I donot limit my invention-to this type as certain'ofm improvements arelikewise dei tosuch an extent as to of tlic terminals caused by ins'ertn 'into the jaws of a fuse block.

.. Fiber, which'is prncipall for electrit fuses,

sii-able in o er. types offuses.

used as s cas not hold its threads i when used 'very often. It willshrink, allowing the fittings attached there;

to to become loo and permit the escape of and flame on the'- blowing ofthe fuse. It wi1l,-When subjected to dampness, swell' make removal of the fittings difficult or impossible.. I have .over-l come these diiculties in a manner that causes the fuse to be more tightly enclosed when the fiber shrinks, and still not affected when the fiber swells. Difficult has been experienced in refinable knife lade fuses by ,reason of the-oontact blades or terminals not being positively aligned with each other. 'When this occurs, th'e jaws of the .fuse block are sprung or bent 'out of shape, resulting in poor contact, and consequent premature burn-out. of the fuse link. I have overcome this troublin a `manner that is absolutely positive'l et so,

I have' alsoeliminated the diiculties experienced by sidewise movement of the terrninals, and have rovided means for sub stantially preventing edge'wse 'movement the fuse is edgewise movement results in injury to the fuse link or loosening of its fastenings, resultingii'i" poor contact and consequent premature burnout ofthe fuse link.

Another object of my invention is to overcome the 'difficulty' that has been experienced in assembling and fastening the fuse link'to the terminals in a straight line. The. difficulty has been that when the bolt intended shows a terminal holding washer. an inside view of the end ring. 6 is u view 1910. Seriali No. 295,367.

forthis purpose is pulled up tight, it invariably u ls 'the terminals out of line with the link, making it'impossible to assemble the fuse. Attem ts to brin the terminals in line with the ink after ing assembled result in injury to the fuse link or loosening of its fastenings.

' A great deal of trouble'is also experienced in the assembling of a refillable fuse by' reason of the fact that in assembling the fusible element,-i. e., theterminals and the fuse link, a variation in length occurs; due. tothe clearance necessary in the bolt holes in vthe terminals and fuse link. lVhen the fusibleelement is assembled short, the fuse cannot be put together at all and must be re-assembled; when the fusible element is assembled long, the, link must be crushed or bent to allow the case to be closed. 'I have overcomethis difficulty ina siniple'manner, by providing means for takingcare f these variations. These and other advantages of m inven- -tion will be more readily understood by reference to the accompanying drawings, which show a preferred embodiment of my invention. In describing the device shown in the "drawings hereto attached .and described in tlie.specifications,'1 do not limit my invention vto the `recise form, shape er construction of the use shown, orto the several partsthereo'f, as various alterations can'be made without' changing the scopeof my invention. 1 l

Fig. 1 is a view of 'my fuse, having a secbroken out to show .the arrangement tlierof. Fi 2 is a view -of tlievfuse ninety degrees from he position shown in Fig 1. Fig. 3 is a view of enclosing washer. Fig. 4 'Fig 5 is of the end of the fuse. 7- is a modification of the ring shown in Fig. 5. 8 is a crosssectional view on theline'-S of Fig. 1.

Fig. 9 shows a view of my fuse having a section broken out to sliowla modified arrangement thereof. tive vii-.w of another modified form. Fig. 11 slio\\'s' :i cross-sectional View of the copper teiiiii'nnl with modified Vlink holding lugs.

` ln the rlia\'i|igs, 9 is acasing which is made -of hard fiber or other suitable material. l0 is a member, preferably of metal,

andreferably in the shape of a riii'g, which ni ciii er is fitted partly within the casing andheld by threads ll l2 is a rivet pre llO venting relative' rotational' -movexixe.ntlA be'- tween-tlfe casing9 andthe member- 13 isa' shoulder on theA member 10. M is the fcap engaging portion thethreads thereon engagin .'w'ith the. threadsof the cap 15.-

-From t -is it/zan-I` be readily seen that by reason of the member being fastened inside .".the casing, the shrinking ofthe ber now serves'to holdthe casing' more firmly to`ithe elementz f YThe cap -engaging .of the -f r`does not revent removal o :the cap; 'the 'shrinking rmitj-the cap t9 becomeloose; the' usedwhen'removing for replacing the c'a -fare 'on the metal por- -ti'o n istead ofthe ber and will not readily.

wear or chip. The-cap may 'be attached by shown.

It. will be readjly,- nnderstood vthat this memberlO ma 'dilferent fo'rms and `may Abe `held a other means, but-,preferably by' tl nead s,"asl

casin'g ,by 'other means does notoverlap. thejbe a's shown in -Fig'. 9, but I prefer this formia's'itdmitsnf the production-of a 'more".attractive and coni venie'n'tly. assembled fuse.'

16 is a an blade -rmnn which keine with'in"'the member. 10. The inner periphery ofi this member is so shaped' that the terminal is prevented from; rotational niovcment. `Whi1e any non-circularinterior will agonal openin as ahown `at f 26`-in F ig. 7, I have foun 'it preferablegtobuse two gmoves foi: thatfpurposef, as shoivn 17 'entire length of'this 1n the same plane and One of theseffmembers n 'ithgrooves or other non-circularjinterioris placed 'on each c nd of the easing, with the grooveprpperly positioned,` so that.the terminals areJheld in substantialalignment with each other.- Y W" '-.These grooves or other form"-of jnoii+eir cular interiorextend preferably throiigligthe' member. They arefof' suoli a dimensionaslwillclosely ltthe teneachgother .between-:which points the terplearanoe. When tlielterminal is subjected to 'edgewisejmovement, as, for instance,

rtion. being ay .be dispensed,

when afuse is inserted in the fuse the' terminalivvill bear on the points er, 2 7 or 28, 28, and by reason o'f the separation 0f these points and the small clearance allowed, only avery limited movement of the terminal ispermitterl, The member must be made of 'a material of practically unchanging dimension, so as to maintain these dimensions constantA Fiber, `as now made, cannot be used for this purpose, as

the shrinkingor swelling of thc fiber would not maintain this constant clearance and would cause the terminals to bind.- I rnay make this member with anxopening oon-A 'siderably larger than the width of the te-rminal and provide projections or'bear-ing. vpoints at the outside and inside ends thereof as shoivn in Fig. J where the terminal is positioned, but 'the-eilect would be the same,- as the terminal will touch at points 27, 27 or 28, 28', as shown.

.` While I have accomplished this result by the use of the 'grooves shown, it is readily apparent that where other means are used for preventing rotational'onsidcwise mo'vement,'that I may dispense with the use of grooves, .asth'e substantial prcventionof edgewise movement-I accomplish by means of the constant relation of bearing points separated from each other. Y It will also be understood that the nieans Aof holding the terminals against rotational movement ment with each other, may be'used' on other forms of fittings within or without the cas- -ing and that while grooves subStantial length are' my' preferred form of construct-ion for the prevention of edgewise and sidewise strain, it canbe readily understood by those -acquainted with the art, tliaft many variations of this arrangement are possible withlil 'invention.

1the above I have described a structure, eomprisin a\casin vand membera at each end, but may ma re thisgaixnitary strncture of insulating material of unchangmg ',diniensions'as shown in Fig. 1 0. -The Aterniinalslo are connected to the fuse link 21 by bolts 22 or other suitable means extending through openings 23 in thelink and terminal. Upon the terminal 16 are lugs placed inv position between them, but substam -tially preventing any sidewise 4movement;

By|reason of the relation of the luga 24 to theopening 23; the fuse link 21 is held in alignment withthe terminals, and'cannot be pulled out of'suclr alignment when-tastenagainst. sidewise movement,- .against edgewise movement, and 1n al gn- -ont-varying from thespirit and nature of ing the bolts. These lugs 'are preferably made by stamping the terminahand'instead of being struck upat-right angles tothe terminals, they 'may be inade tdi'nclineltof' wards-each other in auch Wisel that onlyafuse link cfa predetermined thickness or lees, may be Awithin the lugs as zs'howninF .'11.

The terminal holdin device 19ans. be ot any desired form, alt ough I- pre er the notched washer ahovvn, as it ia especially advantageons in connection with the grooves in the member or ringV 10, as they serve to close`the Vspatie `left open `by that portion of.

the notch inthe washer not engaging the terminal2 thereby completely closing the case. Thisv iav particularly advantageous as it premais dposa of meal on am ramas f:

'fuse linkv for'the bolt which faatens them together. This causes a variation in the length of, -tbev fusible `element l-when f they fare as#` length of the-'structure which consietaofthe casin and closures, which closure might coi1- 'sist o a 'ca alene`,or a cap and washers.: The

querian-hns 'been iniured ,in .an @am @o vlengthen oi shorten" 'the "fugible clement rre frrcd to', so as to' adapt thi's'strueti'ire to the casing and closures. rangement in connection with the structure comprising the terminals and fuse liiiir'1 ao that despite variations inthe length-0f this A structure, or -in the len h -of the structure comprising casing'andc osures; the`fuse may be easily und-quickly assembled without in jury to any part thereof. -Iu'the arrangement shown in Fig. l, I have n'iade the s'pace in the terminal l6`of greater width than theI thickness of the terminal holdin washer '19 shown inFig. 4, that tits vvit in such space. This holds the terminal' against longitudinal movement, except to theextent of the difference between the thickness of the washer und the width of the'slot, which is sulicient to compensate for they variances above mentioned'. This'structiire comprising terminals and strip I have designated as the ,floating clement" when arranged as above iniggested,4 because this member during assemblage moves or oats to admit of adjustment with'the length of casing and clo ainfos, Aand is to he. regarded as broadly' have provided an ara" .the casing, and o lade terminal extending within the member and through the closure, and means on the closurefor engagin the threaded portion of the member outsitliz the casing.

2. In a fuse, a casing, a cap, a cap'holding member detachably engaged by the cap,

'said member having grooves in the inner periphery thereof, and a flat'bladel' :rmiaial positioned within the groovesof the'member.A

3. In a-fuse, acasing,a cap, a fuse element comprising fiat blade terminala, fuse link and connection means' therefor, a. cap

holding meinberpdetachably engaged by-'tlie` cap and havingits interior so shaped that 'the fuse element may be assed therethrongnand yet Vpc'rsitioned therein .against rotational movement. v, 4.111 a renewable knife' blade cartridge fuse, the combination oi a casing, a threaded ca' -a metallic ea holding member threa ed within the en s of the'casing and extending'beyond the easing, threads on a portion of the c'ap holdin member beyond the casing,v said member aving oppositely .spaced recesses at the outer end Athereof adapted to engage a part of the terminal and limit the rotational movement of the ter` minal.v v y 5. In arellable fuse, a. tubular casing, a closure, a at blade terminal arranged to ass through the cusingpa member distinct rom the closure Permanently attached to practically unchanging dimensions adapted to 'extend about. the terminal,said member having on its inner p'eriphery substantiall -se arated points on each-of opposite sides t creci, said points having a' constant spaced relation to each other and acting sa bear' points-between which points the te'rniinaLlliaving-a. certain limited clearance, iiiremovably positioned, whereby `the edgewise movement of .the ter prevented.

6. In'a reillahlc fuse, a flat blade tcri minal, a casing and imeans beyond the end o .f the casing concting with means on the terminal for allowing'the terminal a certain limited longitudinal movement `relative to the. casing. Y

7. In :i refillable fuse, n flat blade terniinal-,a threaded cap and-means held by the cap eoacting with means on the terminal for allowing the terminal a certain limited longitudinal movement ielativeto the casi ng.

8. ln a retillable fuse, e at'blade terminal, n casing, a Cap, a terminal holding device adapted -to be pressed by `the can and means on the terininai enacting with said device for allowing the terminal a certain limited longitudinal movement relative to the casing. A

i). lnl :i retllable fusc,a casing, a that blade tei'iiiinal7 a terminal holding device, a cap adapted to be put on and 4renioved'independei'itly of the terminal holding device and means on the terminal coacting with said device for allowing the'terminal al1 oerltain limited lonvitudinal movement re at-ive C v v".minal and coacting with the member to 'close to the casing.

10. In combination witha structure vcom- 'prisiiig a easing and closing structures therefor,.a structure comprising terminals and a fuse. link, one f said structuies having means beyondtlie endjof the casing coacting with means on the other'structure forvconi pensating variations between the-lengths of the two structures; i, 11.' In a refillable fuse, a casing, a closure, a Hat' blade terininaladapted to be passed through the casing, a member coniiecting casing'andiclosureand having within -it means-of pract'ca'lly'-constantspaced "Hat blade terminal, a Cap relation for positioning the terminal against rotational movement.

12. In'al renewable fuse" off the iiniill'ed type, n fibre'casing', a caga-metallic mem-- ber externally threaded within an end. of

the casing and having'an externally threaded poi-tion beyond' the casing, a'terminaljexf tending within Athe member and' through the cap,'nieans between the metallic member and Athe cap adapted to hold theterminal i against longitudinal movement relative to `the casing, 'and means on the cap for engaging 4the threaded portion 'of the' member 'outside tlie casing.A 13` In a refillable fuse, aj casing, a ilat blade terminal arranged to' pass thoughthe casing, a-cap, a cap.holding member pervmanently attached to the casing having substantially 'separated points. of constant spaced relation to each other on each of the opposite" parts of the inner .periphery of ist said member,- between wfhich points the terininzil, having-a. certain limited clearance,

- is removably positioned, whereby the'edge- -wise movement of the terminal relative tothe casing, is substantially prevented.

14. In a refillable f iise, a casing, a capholdin member `attached to the casing, a fuse efementeoinprising a fiatf blade teriiiinaLand a fuse link connected' thereto', which are 'adapted to be passed'througli the member and means oti'the inside ofthe mem.

againstsidewise movement.

i 15. In a retillable fuse, a casing, a cap holdin -attached to the casingfa fuse .e ement 'comprising a dat 'blade terminal and l fuse link' attached thereto, which' are ada to be passed throu li thenieinbei-,'-andxneans 'within the mem -of 'practcally-oonetant spaced relation for substan- 'Qalljfpreventingthe axial and'edgewise movement ot the terminal. '16. Ina refillable fuse, `a casing, a cap, a

- ber for substantiallyholding the terminal i externally metallic cap holding member attached to the ca' easing, a fiat blade terminal havinr its edges tittingwitliin and closely bordered by faces of said. member -and a terminal holding de vice adapted to hold the terminal against longitudinal movement, fitting about the ter- 7o .of the terminal is substantially prevented.

18. 'In'a retillable use, a casing,V a capya holding member permanently attached to tlie casin and de- Si tachably engaged b the cap, sai member having oppositely is'posedfdevices in' con-A etantspaced. relation 'with each other, within which the terminal i's removably positioned,'. whereby rotational and edgewise movement 90 issubstantiallyprevented.- vv19.` In a. renewable knife blade cartridge fuse, a.-

a vmetallic member threaded within the endof the casing and having'an externally .threaded portion extending -beyoud the casing, a, transversely movable termi'nal holding device outside the end of the metallic member, a knife blade terminal extendingwithin the metallic member and ha means for engagement with the ter- 100 minal liol'diri'g device and a, closure element threaded fon a portion of the metallic membe'r be ond the 20. .ai renewable knife blade cartridge fuse, a casing, a metallic cap holding ineinaber threaded into the easing and having a.

'fitted *around4 the terminalof a size greater than the' aperture in the cap holding inem- A1 1@ ber, and acap adapted to be threaded on the cap holding mef'nber and compress the washer against the terminal holding means.

2l. In aknife blade renewable fuse of the unfilled type,- atibre easing, a. metallic mem- 1W ber havin external reads engagin threads wit in the end' of the casin 'an having an externally threaded sliou dered Y portion outsidethe' casing,a knife blade ter'- minal adapted to extend within said inem- 12s ber and f'elosureolement screwed on the V"threaded sshouldered portion of said member.

'22. In a reillablefuse, the combination of a fuse element comprising terminals and fuse link and an enclosing 'structure having en`dsx whose outer periphery 'is arranged to removably hold a cap land whose inner periphery is so sha ed that the fuse element may be positione therein against rotational movement..

23. In a renewable knife .blade fuse of the unfilled type, a fibre casing having threads on its interior at an endthereof, a knife blade terminal, a closure means oftsiibstantially unchanging dimension, adapted to substantially close the end of the casing, cx-

cept 'for .an opening through which the re-;

movable knife blade terminal closely'fi-ts and extends outwardly; saidclosure means having threads 0n its exterior periphery engagwhereby the shrinking of the libre contributes to -increase the engagement of the threads of the casing with this" threads f blade terminal, u closure means of snhslan- A` tially unchanging dimension, adapted In substantially close .the end of the easing, except for an opening through which the removable knifeblade terminal closely lits and extends outwardly, and means on the knife blade terminal cnaciingirith the elosure mcansffor limitingr the long ftmlilml movement -ofjth'el terminal; "said closure means having'thrcnds on its exterior pcriphery engaging the thx-muis in the fibre casing, whereby Vthe shrinking of the libre contributes to increase the engagement of the rthreads of'the' casing with the threads of the'elosure means.

HENRY T. BUSSMANN. 

